Superconducting Cable Terminal Managing Thermal Expansion

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Solution Overview

Problem

Existing terminal connecting parts for superconducting cables face challenges in effectively absorbing thermal expansion and contraction, leading to local stress concentration and reduced flexibility, especially when dealing with both horizontal and vertical directions, and often require complex structures and large axial forces.

Innovation Solution

A terminal connecting part that allows the cable core to move longitudinally and rotate circumferentially, using movable connecting terminals with conductive contacting terminals, such as coil springs, to maintain electrical connection while absorbing thermal expansion and contraction, and includes a dual-lead configuration with a slidable coupling to manage thermal expansion in the vertical direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the cable core is fixed rigidly to prevent movement, then structural stability is improved, but thermal expansion and contraction cause local stress concentration and buckling

Engineering Contradiction:

Improvestructural stabilityVSAvoidlocal stress

Core Design Contradiction:

Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The patent applies the dynamics principle by introducing a movable connecting terminal that allows the cable core to move dynamically in response to thermal expansion and contraction. The connecting terminal includes a movable portion that can displace along the cable core's longitudinal direction, transforming the rigid fixed connection into a dynamic adaptable connection that absorbs thermal stresses without causing buckling or stress concentration.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If flexible connecting terminals are used to absorb thermal expansion, then flexibility is improved, but the terminal structure becomes complex and requires large axial forces

Engineering Contradiction:

ImproveflexibilityVSAvoidterminal structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the connecting terminal into distinct functional portions: a fixed portion attached to the current lead and a movable portion attached to the cable core. The movable portion is further segmented into elements that can independently displace, allowing thermal expansion absorption through simple relative movement between segments rather than requiring a complex flexible structure throughout the entire terminal.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The movable portion of the connecting terminal acts as an intermediary element between the fixed current lead and the cable core. This intermediary component absorbs thermal expansion and contraction through its own displacement, protecting both the cable core and current lead from stress while maintaining electrical connection, thereby simplifying the overall terminal structure compared to making the entire terminal flexible.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the cable core is allowed to move longitudinally, then thermal expansion management is improved, but electrical connection stability may be compromised

Engineering Contradiction:

Improvethermal expansion managementVSAvoidelectrical connection stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The movable connecting terminal dynamically adjusts its position to accommodate cable core movement while maintaining continuous electrical contact. The movable portion can displace along the longitudinal direction during thermal expansion and contraction, ensuring that the electrical connection between the cable core and current lead remains stable and reliable throughout the thermal cycle without compromising connection integrity.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design effectively prevents stress concentration, maintains cable integrity, simplifies the terminal connecting part, and reduces axial forces, allowing for efficient thermal expansion and contraction management in both horizontal and vertical directions.

Implementation Method 1

conductive contacting terminals, such as coil springs, to maintain electrical connection while absorbing thermal expansion and contraction

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the cable core 11 thermally expands and contracts at about 0.3% of the length of the superconducting cable

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9251932B2Terminal connecting part of superconducting cable

Publication Date: 2016.02.02 FURUKAWA ELECTRIC CO LTD

AI summary

A terminal connecting part has: a low temperature container filled with a cooling medium; a conductor current lead which has one end immersed in the cooling medium and the other end led to a normal temperature part; and a conductor movable connecting terminal which electrically connects a superconductive conductor layer and the conductor current lead of a superconducting cable. The superconductive conductor layer of the superconducting cable stripped stepwise from a front end is connected to the conductor current lead through the conductor movable connecting terminal. The cable core of the superconducting cable is movable in a longitudinal direction and is rotatable in a circumferential direction while maintaining electrical connection between the superconductive conductor layer and the conductor current lead. The cable core is horizontally supported in the low temperature container.